mci-step

Arguments:
device &key notify-p wait-p (frames 1) reverse-p

Steps device by the indicated number of frames forward unless
reverse-p is true. If the :wait-p argument is specified true, this
function will not return until the action is completed. If nil, this function is run asynchronously. If
notify-p is true, mci-notify will be called when this
function completes.